Google Image Search

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already provide readOnlyHint=true and openWorldHint=true. The description adds behavioral details: results are cached for 30 minutes and it uses the Google Custom Search API, which is consistent and adds value beyond annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, with clear sections (purpose, when to use, key parameters, caching). Every sentence adds value, and the structure is front-loaded with essential information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity (8 parameters, high schema coverage, output schema exists, annotations present), the description is complete. It covers API, filtering options, and caching, leaving no obvious gaps for an AI agent to use the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Input schema covers 100% of parameters with descriptions. The description goes further by summarizing key parameters (size, type, color_type, file_type) with their enum values, making it easier for an agent to understand relevant filters at a glance.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it searches for images using Google Custom Search API and specifies what it returns (image URLs, thumbnails, dimensions, source page URLs). It effectively distinguishes this from sibling tools like google_search (general web search) and google_news_search (news).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description includes a 'When to use' section listing use cases like finding visual content and needing specific formats/sizes/colors. While it implies alternatives by context, it does not explicitly name sibling tools or state when not to use this tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.